Question 6-pin and 8-pin PCIe power connectors ?

Sep 11, 2022
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Hey all,

i just got an MSI RTX3070 to replace my EVGA RTX2070S and the first thing I noticed is the new card has 2 x 8-pin PCIe connectors whereas the 2070 has 1 x 8-pin and 1 x 6-pin.
All I have coming out of my PSU is one 8-pin (6+2) and a 6-pin. What’s the best solution? Adapter? My PSU is 800 watt.
 

DSzymborski

Titan
Moderator
Need the exact PSU. An 800W PSU that only has a 6+2 pin and a 6-pin connector is highly suspicious. Most of the ones in that case are "800W" PSUs, not 800W.

An adapter is very rarely the exception. Powering a 3070 with an adapter, possibly from a junk PSU, is not one of those exceptions, unless you're hoping to make a YouTube video about your computer fire.
 

Karadjgne

Titan
Ambassador
Not going to work as planned. A 6pin has 2x 12v wires and a sense wire on the top level and 3x grounds on the bottom. When you put that into a 6pin receptacle, the gpu sees the sense wire and knows its a 6pin. The +2 are another sense wire and a ground. When joined with the 6pin, the gpu sees the 2nd sense pin in the right position, the original sense becomes a standard 12v.

By using the 6pin to 8pin adapter, that doesn't happen and you end up trying to pull 150w through wires rated at 120w.

There's reasons why adapters of that kind are strongly advised against in use. Adapting to the same, but different, is one thing, like an 8pin to 2x 6pin is ok. But using an adapter to 'create' more is totally different. One is safe, the other is a fire hazard.

An 800w psu should have 2x 8pin/2x 6pin capability. Meaning you are simply missing the correct wiring from ibuypower. You need the right 6+2 pin connections. If that psu is not modular/semi-modular, and is hardwired, then the obvious conclusion would be its simply not designed for that kind of 12v outputs, and the 800w is purely fictional.
 
Sep 11, 2022
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We’ll the 2070 has an 8 and 6 port connectors. So it makes sense the words from the PSU are also 8 and 6… so what’s the solution? New PSU? I’ll just send the thing back and get a refund if that’s the case and stick with 2070.
 

DSzymborski

Titan
Moderator
We’ll the 2070 has an 8 and 6 port connectors. So it makes sense the words from the PSU are also 8 and 6… so what’s the solution? New PSU? I’ll just send the thing back and get a refund if that’s the case and stick with 2070.

It actually doesn't make sense at all; a quality 800W PSU will come with far more connectors than that. They're not designed to target one specific GPU. The Corsair RMX 850, Super Flower Leadex Gold 850, and EVGA G6 850 all come with six 6+2 pin connectors.

The solution would be a new PSU. Returning is not a good solution, either, replacing the PSU is; if it shouldn't be powering a 3070, it usually shouldn't be powering a 2070 either. The cheap boutique companies like iBuyPower are notorious for putting cheap PSUs in as their "standard" offering since the PSUs and the parts powered by the PSU only have to last for a year they cover their parts under their standard warranty (and MSI doesn't have to replace a possibly fried 2070 either; as a reseller, ibuypower gets a warranty from MSI, not you). All you need is a mediocre-but-efficient PSU and most people who buy prebuilts will equate 80 Plus Gold with a quality rating rather than simply power efficiency.
 
Sep 11, 2022
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Well there very well may be more connectors/connections burried under there, they may have just done it that way becuse of what was required of the 2070S. I’ll have to take a look. I’m a total novice obviously and didn’t want to have to dig into the PSU but it looks like I may have to bow. Not sure if it’s modular or not.
 

DSzymborski

Titan
Moderator
Well there very well may be more connectors/connections burried under there, they may have just done it that way becuse of what was required of the 2070S. I’ll have to take a look. I’m a total novice obviously and didn’t want to have to dig into the PSU but it looks like I may have to bow. Not sure if it’s modular or not.

Unfortunately, it's the key bit of information for any GPU advice; a proper, quality PSU is the most important part of your PC. Learning what the parts in your PC are and why different things are recommended is one of the best ways to advance past being a novice, with the nice side effect of saving you a lot of money over the long haul.
 
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If its an 800 watt unit and its a decent brand, and since its a prebuilt, I've ran into this situation before, I've used these in the past and never had an issue, heck most psu's are wired like this anyway for the 8 pin, yeah its not pretty, but its still safer than them molex connectors. https://www.amazon.com/Cable-Matters-2-Pack-6-Pin-Adapter/dp/B01DV1Z32Y

Some people won't like these and give me crap for it, but like I said, even some mid to higher-end PSU's are wired the exact same way with the little pig tail to convert a 6 to an 8 pin with only 6 wires, the 3070s dosn;t chew up enough power to anyway to really need true 8 + 8 pin anyway.

Its either that, to replace the PSU, which I would if its not a really good brand.

Good Luck!
 

DSzymborski

Titan
Moderator
If its an 800 watt unit and its a decent brand, and since its a prebuilt, I've ran into this situation before, I've used these in the past and never had an issue, heck most psu's are wired like this anyway for the 8 pin, yeah its not pretty, but its still safer than them molex connectors. https://www.amazon.com/Cable-Matters-2-Pack-6-Pin-Adapter/dp/B01DV1Z32Y

Some people won't like these and give me crap for it, but like I said, even some mid to higher-end PSU's are wired the exact same way with the little pig tail to convert a 6 to an 8 pin with only 6 wires, the 3070s dosn;t chew up enough power to anyway to really need true 8 + 8 pin anyway.

Its either that, to replace the PSU, which I would if its not a really good brand.

Good Luck!

Yuck. It's one thing to use cheap adapters on your own PC, it's another thing entirely to recommend someone else use them.
 
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And since we DON'T know the specific PSU, suggestion of any adapters is irresponsible at best.

A 'decent brand' 800 watt PSU wouldn't need any adapters. It would natively have the proper connectors.
And you didn't read half of what I wrote, that's the problem with today's society, just read what they want, but not whats in front of them! I'm not going to say it twice to those who skimp over.

Good luck everyone.
 
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6pin cables can support far greater throughput than the PCI-SIG suggestion of 75w.
You can drive your car around for 8 months on a temporary doughnut spare too, but that doesn't make it a good idea. Eventually, something bad is going to happen. In this case, it's likely a very close comparison. And on a cheap Highpower unit out of an even cheaper iBuypower PC prebuilt, an even worse idea. This is not a quality unit and the sooner you replace it with something that is, the sooner you'll have no need of this discussion because you'll have a power supply with the proper connectors.

I've said this many times before but it's always worth saying again.

ANY manufacturer could put any number and type of connectors on any power supply they make and sell. The fact that it DOES NOT have a certain type of power connector on it means THEY KNOW, WITHOUT ANY DOUBT, that the unit is not only incapable of supporting that connection but that it's unsafe to even attempt it. Using something that distinctly goes around the roadblock that the manufacturer THEMSELVES put directly in your path, is simply begging for the temporary tire to blow out while going down the freeway at 75mph.

Any PSU that can safely and legally support a specific type of connector WILL COME WITH IT. If it doesn't come with it, then even the manufacturer is saying "this is a bad idea". Hard to argue with that. Especially when you already KNOW it's a bad idea.
 
You can drive your car around for 8 months on a temporary doughnut spare too, but that doesn't make it a good idea. Eventually, something bad is going to happen. In this case, it's likely a very close comparison. And on a cheap Highpower unit out of an even cheaper iBuypower PC prebuilt, an even worse idea. This is not a quality unit and the sooner you replace it with something that is, the sooner you'll have no need of this discussion because you'll have a power supply with the proper connectors.

I've said this many times before but it's always worth saying again.

ANY manufacturer could put any number and type of connectors on any power supply they make and sell. The fact that it DOES NOT have a certain type of power connector on it means THEY KNOW, WITHOUT ANY DOUBT, that the unit is not only incapable of supporting that connection but that it's unsafe to even attempt it. Using something that distinctly goes around the roadblock that the manufacturer THEMSELVES put directly in your path, is simply begging for the temporary tire to blow out while going down the freeway at 75mph.

Any PSU that can safely and legally support a specific type of connector WILL COME WITH IT. If it doesn't come with it, then even the manufacturer is saying "this is a bad idea". Hard to argue with that. Especially when you already KNOW it's a bad idea.

Thank you for adding that extra information, it's always great to make an informed decision before taking a risk.
Good idea or not, I'd still run it.
 
Sep 11, 2022
18
0
10
If its an 800 watt unit and its a decent brand, and since its a prebuilt, I've ran into this situation before, I've used these in the past and never had an issue, heck most psu's are wired like this anyway for the 8 pin, yeah its not pretty, but its still safer than them molex connectors. https://www.amazon.com/Cable-Matters-2-Pack-6-Pin-Adapter/dp/B01DV1Z32Y

Some people won't like these and give me crap for it, but like I said, even some mid to higher-end PSU's are wired the exact same way with the little pig tail to convert a 6 to an 8 pin with only 6 wires, the 3070s dosn;t chew up enough power to anyway to really need true 8 + 8 pin anyway.

Its either that, to replace the PSU, which I would if its not a really good brand.

Good Luck!
I ordered that very connector yesterday. I’m going to dig around in the PSU when I get home today and see the specs, and if there is another 8 pin connector hidden in there that they may not have used because the 2070S is a 6 and 8 pin connector. Looks like the 3070 only pulls 5 more watts than the 2070S (215 vs. 220) and the 2070 uses a 6 pin.